Lest {spatstat}R Documentation

L-function

Description

Calculates an estimate of Ripley's L-function for a spatial point pattern.

Usage

  Lest(...)

Arguments

... Arguments passed to Kest to estimate the K-function.

Details

This command computes an estimate of the L-function for a spatial point pattern. The L-function is a transformation of Ripley's K-function,

L(r) = sqrt(K(r)/pi)

where K(r) is the K-function.

See Kest for information about Ripley's K-function.

The command Lest first calls Kest to compute the estimate of the K-function, and then applies the square root transformation.

For a completely random (uniform Poisson) point pattern, the theoretical value of the L-function is L(r) = r. The square root also has the effect of stabilising the variance of the estimator, so that L is more appropriate for use in simulation envelopes and hypothesis tests.

Value

An object of class "fv", see fv.object, which can be plotted directly using plot.fv.
Essentially a data frame containing columns

r the vector of values of the argument r at which the function L has been estimated
theo the theoretical value L(r) = r for a stationary Poisson process

together with columns named "border", "bord.modif", "iso" and/or "trans", according to the selected edge corrections. These columns contain estimates of the function L(r) obtained by the edge corrections named.

Author(s)

Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner r.turner@auckland.ac.nz

See Also

Kest, pcf

Examples

 data(cells)
 L <- Lest(cells)
 plot(L, main="L function for cells")

[Package spatstat version 1.16-0 Index]